This spectacular, full-color image of the Earth is a composite of the
first full day of data gathered by the Moderate-resolution Imaging
Spectroradiometer (MODIS) aboard NASAs Terra spacecraft. MODIS
collected the data for each wavelength of red, green, and blue light
as Terra passed over the daylit side of the Earth on April 19, 2000.
Terra is orbiting close enough to the Earth so that it cannot quite
see the entire surface in a day, resulting in the narrow gaps around
the equator. Although the sensor's visible channels were combined to
form this true-color picture, MODIS collects data in a total of 36
wavelengths, ranging from visible to thermal infrared energy.
Scientists use these data to measure regional and global-scale
changes in marine and land-based plant life, sea and land surface
temperatures, cloud properties, aerosols, fires, and land surface properties.

Notice how cloudy the Earth is, and the large differences in
brightness between clouds, deserts, oceans, and forests. The
Antarctic, surrounded by clockwise swirls of cloud, is shrouded in
darkness because the sun is north of the equator at this time of
year. The tropical forests of Africa, Southeast Asia, and South
America are shrouded by clouds. The bright Sahara and Arabian deserts
stand out clearly. Green vegetation is apparent in the southeast
United States, the Yucatan Peninsula, and Madagascar.